The outward exposure of roofs causes great amounts of heat to be developed at the roof and the underlying structure. To dissipate this heat ventilated roofing systems are well known. A roof cover may have a panel or series of panels overlying another panel or roof so that a space is created between the two. The upwardly sloping passageway formed between the two permits the upward circulation of air thus having a cooling effect. However, the cooling effect is minimized by barriers impeding the free flow of air.
In addition where there is a roof underneath an upper roof panel it is not intended to carry rain water. Where air is permitted to flow upwardly there is a venting arrangement which prevents water flow. U.S. Pat. No. 5,473,847 to Crookston is illustrative of a ventilated roofing system. The vent of Crookston permits air to flow but a shield excludes any moisture or rain from the lower roof panel. None of the openings are exposed to the ambient. It would be desirable to provide a roof with a more efficient cooling system.